Red Lion LEGEND - Manual (Page 55)

SIGNAL WIRING
INPUTS A & B
Input A and Input B have the same input circuitry and share the same common.
Input A and Input B each have separate DIP switches for setting the type of signal
input. A Magnetic Pickup or Logic Input signal can be sent to either input. When a
MAGNETIC PICKUP is used, the Sink/Source DIP switch, for the appropriate
input, must be in the “SRC” position or the unit will not receive the signal. The
HI/LO FRQ DIP switch affects the maximum input frequency at that input.
The Input schematic shows the details of Input A and Input B circuitry. Each
input has three DIP switches associated with its input. The functions of these
switches are as follows:
INPUT A
SW1 - MAG: Sets input for a Magnetic Pickup signal.
Sensitivity: 200 mV peak; hysteresis: 100 mV
LOGIC: Sets input for a Logic signal.
Input trigger levels: V IL = 1.5V max; V IH = 3.75 V max.
Note: SW2 must be in the “SRC” position for a Magnetic Pickup signal.
SW2 - SNK: Provides a 7.8 K W internal pull-up resistor for sensors with
current sinking outputs.
SRC: Provides a 3.9 K W internal pull-down resistor for sensors with
current sourcing outputs.
SW3 - HI FRQ: Removes damping capacitor and allows operation up to
the max. frequency.
LO FRQ: Connects damping capacitor for switch contact debounce.
Limits count speed to 50 cps max. Min. count pulse ON or OFF time is
10 msec.
Note: The HI/LO FRQ selection switch must be set on “LO FRQ” when switch
contacts are used to generate count input signals. The “LO FRQ” mode
provides very high immunity against electrical noise pickup. It is
recommended that this mode also be used, whenever possible, with electronic
sensor outputs. The “LO FRQ” mode can be used with any type of sensor
output, provided count pulse widths never decrease below 10 msec, and the
count rate frequency does not exceed 50 Hz. INPUT B
SW4 - Same as SW1
SW5 - Same as SW2
Note: SW5 must be in the “SRC” position
for a Magnetic Pickup signal.
SW6 - Same as SW3
Note: A Magnetic Pickup type sensor should not be used unless a large enough
signal is provided at all speeds of operation.
-53-